/Engine/Source/Runtime/RenderCore/Public/PipelineCacheUtilities.h
The cache file is saved together with the stable shader keys file that were used to map its hashes to the build-agnostic ("stable") shader identifier.
namespace UE { namespace PipelineCacheUtilities { bool UE::PipelineCacheUtilities::SaveStablePipelineCacheFile ( const [FString](API\Runtime\Core\Containers\FString) & OutputFilename, const [TArray](API\Runtime\Core\Containers\TArray)< [FPermsPerPSO](API\Runtime\RenderCore\FPermsPerPSO) > & StableResults, const [TArray](API\Runtime\Core\Containers\TArray)< [FStableShaderKeyAndValue](API\Runtime\RenderCore\FStableShaderKeyAndValue) > & StableShaderKeyIndexTable ) } }